This invention relates generally to means for closing the filler tube of containers such as fuel tanks, and the like, and more particularly to a safety type closure assembly which prevents fuel vapors from escaping from the fuel tank at the time of refueling a vehicle or pumping fuel into a container.
In conventional type fuel systems for motor vehicles, a vented type of filler cap is screwed on or otherwise secured to the outer end of a filler tube to prevent fuel loss from the fuel tank. The filler caps take many forms and some even include filter elements which operate to filter incoming air and/or prevent dirt from entering relief valve assemblies while in position on the filler tube.
However, when one proceeds to refuel or otherwise add fuel to the tank, the filler cap must be removed and the operator must then insert a fuel delivery nozzle into the top of the filler tube which at the same time opens a spring loaded flap valve located at the outer end of the filler tube. In doing so and during the course of a filling procedure, fuel vapors in the tank and the filling tube rise and escape to the surrounding environment. The resulting fumes not only have a noxious affect on the person(s) in the immediate vicinity, but can result in sickness and headaches in persons breathing the vapors and in some cases eventually causes and/or aggravates respiratory illnesses in such person(s).
It is an object of the present invention, therefore, to provide an improvement in closures for fuel tanks.
It is a further object of the invention to provide an improvement in fuel tank closures which is of a relatively simple construction for preventing the outflow of fuel vapors from a fuel tank during a filling procedure.
It is yet another object of the invention to provide an improvement in closure assemblies for fuel tanks which act to decrease pollution of the environment and decrease the health hazards associated with breathing fumes associated with fuels used to power internal combustion engines.
And it is still another object of the invention to provide an improvement in closure assemblies for fuel tanks which permit refueling without removing the closure assembly from the filler tube of a fuel tank.